I am new to chickens myself. I know they say you should incubate them for awhile to make sure they aren't sick. Of course, my husband just puts them in there with them. We have done this several times adding to our exsiting flock and usually goes well a little pecking but not bad. The first time we added 2 EE's. They stayed on the roost most of the time. Would get down and eat while the others freeranged. Then we added 2 Autralorps. There was some fighting that evening but after that it has been fine. Then we added 3 BCM and 1 BCM chick. I was worried mostly about the chick but it has all gone fine. There is gonna be some pecking !

I'll be interested in seeing what others say. I have heard that a "see but not touch" arrangement is good -- like putting them in a pen next to your existing birds so they get used to the idea of each other before they hang out together.

Unless you hatched the chicks yourself or got them from a reputable hatchery, you should start with a quarantine time. Generally 2 to 3 weeks worth of time will give you an indication of whether the birds are healthy. Otherwise you risk bringing in disease to your healthy flock.

Then you decide how aggressive your birds are - would they be okay with you just putting the new birds in the coop? If so, after everyone falls asleep move the three new birds onto the roost and listen in the morning to see how things are going. That is the time of day when I merge my chicks into the larger flock.

If you aren't sure how things will go or how aggressive your birds will be with these outsiders - then you can do the side-by-side thing for a week or so. Let them be in a run/coop nearby but not in the same area as your current flock. In the past I've created an exercise pen out of tomato cages and chicken wire. Then after they've heard each other and seen each other for about a week - I let them all be together, either freeranging or in the same run. And again keep an eye on how things go. Make sure there are places for the hens to hide if they are getting attacked. Only interfere if there is aggressive blood letting going on.

There will be some pecking and squawking because they'll have to establish a new pecking order. But what will probably happen is the 3 new ones will stick together as a subflock. Eventually they may merge into the larger flock especially once the rooster starts mating them. He won't need much encouragement to mate the new hens if he's like my Foghorn. He had no trouble mating the 3 younger pullets that were merged into his care.

Hope everything works for you - chickens are cool to watch when they are establishing their pecking order - I like to try to guess who will be the head hen.

As long as the birds appear healthy and don't have any problems I've never quarantined them. I started off with 2 birds and now have 10. There have always been some pecking, but nothing that bad. I had one time with chicks and they lived in a cage in the coop because they were small.

I didn't have a roo though, I added them last after the girls were established.